There are known procedures for the production of non-woven fabrics produced with mechanical needle-punching and spunlace or hydroentangled technologies and/or optionally subsequently bonded by means of thermal bonding of thermoplastic fibers and/or by adding resins or latexes in general.
These non-woven fabrics are used to produce cleaning cloths or to produce mops. According to prior art techniques to produce needle-punched non-woven felts with mechanical needle-punching systems, these felts are optimally used to produce cleaning cloths, and have the advantage of having a low density and consequently a relatively high volume with respect to the weight per square meter. Moreover, regardless of the type of fibers used, their mass creates a mechanical volume that increases their absorption capacity. Their volumetric mass with low weight density per cm3 also allows the production of articles such as mops or swabs that must have a volume in addition to a cleaning surface. Cloths obtained with this process are formed by fibers with a fineness greater than 1 dtex (macrofibers) and are produced by subjecting both surfaces of the fiber layer to mechanical needle-punching, optionally followed by a thermal bonding process to increase the mechanical consistency of the cloth, or using chemical binders such as acrylic resins, EVA, rubber latexes and the like by means of spray application, impregnation using padding machines or by coating or the like according to prior art. The disadvantage of this type of technology if used to produce microfiber non-woven fabrics is that the majority of the fibers remain inside the thickness of the non-woven fabric and accordingly their cleaning capacity is not used: therefore costs are also higher due to the use of microfibers for the whole thickness of the non-woven fabric structure.
With another prior art technique, known as spunlace or hydroentangled, non-woven fabrics are produced with a higher weight density, generally greater than 0.16 g/cm3, with respect to those produced through the mechanical needle-punching process: these fabrics have the characteristic of greater compactness and low thickness with respect to non-woven fabrics produced with mechanical needle-punching systems having the same basis weight per square meter and the same fiber composition. Said process is generally used to produce microfiber non-woven fabrics as it also splits the splittable microfiber into filaments: it is performed on both surfaces of a mat of extruded continuous filaments deriving from microfibers coming from production systems using spunbonded and/or meltblow technologies or from staple fiber mats coming from carding systems.
The drawback of this production process is that to obtain a thickness that is sufficiently high to allow easy handling for use as cleaning cloths, or to produce strip mops, the weight per square meter of the product must be greatly increased, thus increasing costs due to the quantity of fibers used. Moreover, increasing the weight of the product in this way leads to high production costs, as high pressure water jets are required during the hydroentanglement process to achieve bonding of the fibers inside the layer of non-woven fabric.
Another type of non-woven fabric is represented by microfiber and macrofiber bonded materials produced by thermal bonding of a microfiber layer with a macrofiber layer, optionally subsequently calendering the double layer thus obtained, where each layer has been prepared previously according to the techniques described above. However, this thermal process is costly from the viewpoint of energy and due to the use of hot melt glues which are required to allow adhesion of the two different layers.